SERLS CEMETERY, Donahue Road south side, GILES COUNTY TENNESSEE
This is what I believe from looking at the information on a special census and grave and marriage analysis page I developed using Ancestry.com and these records. Some conclusions have no perfectly clear evidence  where I used error analysis.
Nancy E. (Serls) (Randle) West married James N. Randle sometime around the time Alfred West married Eunice Robinson. Not seen a record on that.
Nancy E. then married Alfred West a widower of Eunice Robinson West about 1866 No marriage record found
Eunice Robinson West married Alfred West on 15 Sep 1839
Eunice was born about 1814 & lived until about 1864. Her ages are consistent in the 1850 & 1860 Censuses but death year estimated between census and death of James N. Randle
Alfred West changed name to Willis West in the 1870 Census after marrying Nancy E. Serls Randle West about 1866, but went back to Alfred after that.
Nancy E. Serls Randle West age is consistent as being born about 1814 in the 1870, 1880 & 1900 Censuses. The burial record is consistent with the censuses
Nancy E. Serls Randle West died between 1880 & 1900 or according to the grave record 1890 which is all consistent
I also believe the Nancy E. West in 1860 home of Alfred West is the same as Nancy A. West of 1870 Census.
I do believe there is little chance that Nancy E. and Eunice are the same person because of the consistent age differences in the censuses as married to Alfred West because she was buried back in her home graveyard of her parents
There is a real possibility that Henry and Anna (Beasly) Serls, parents of James A. Serls are interred in this cemetery in unmarked graves. That is because the censuses give them all about the same family household locations in the census of 1850 & 1860 as the James N. Randle family which is known to be here among the later Serls family members.
Further proof here of the relationship I am outlining is there is a Nancy Randle living in the household of Nancy E. & Alfred West in the 1870 census. Nancy Randle had a daughter named Nancy A. Randle and this shapes up to be her.

Analysis by C. Wayne Austin using Ancestry.com and graveyard records on this site 11 May 2017